In vivo multiphoton diagnostic detection and imaging of a neurodegenerative disease

Abstract

The present invention is directed to a method of detecting a neurodegenerative disease in a mammal by activating brain tissue of the mammal by application of radiation under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to emit a fluorescence characteristic. The fluorescence characteristic is then compared to a standard fluorescence emitted by exciting healthy brain tissue of the mammal under the same conditions used to carry out the activating step. Brain tissue where the fluorescence characteristic differs from the standard fluorescence is identified as potentially having a neurodegenerative disease. Another aspect of the present invention is directed to a method of producing an image of brain tissue from a mammal by activating brain tissue of a mammal with radiation applied under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to produce fluorescence. The fluorescence is then collected to produce an image of the brain tissue.

1. A method of detecting a neurodegenerative disease in a mammal comprising:
 activating brain tissue of the mammal by application of radiation from a laser through an opening or a thinned portion of the mammal's skull under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to emit a fluorescence characteristic, wherein the radiation is at an intensity level capable of being achieved by a titanium sapphire mode locked solid state laser and has a wavelength in the visible red to the infrared region of the light spectrum and is pulsed at a pulse width between about 10 −9  to 10 −15  second, said fluorescence characteristic being achieved by combining photons; 
 comparing the fluorescence characteristic to a standard fluorescence emitted by exciting healthy brain tissue of the mammal under the same conditions used to carryout said activating; and 
 identifying the brain tissue where the fluorescence characteristic differs from the standard fluorescence as potentially having a neurodegenerative disease. 
 
   
   
     2. The method according to  claim 1  further comprising:
 treating the brain tissue with at least one photo-active agent prior to said activating. 
 
   
   
     3. The method according to  claim 2 , wherein the standard fluorescence is determined prior to said treating the brain tissue with at least one photo-active agent. 
   
   
     4. The method according to  claim 2 , wherein the photo-active agent fluoresces upon binding to lesions of neurodegenerative disease or other neuroanomalies. 
   
   
     5. The method according to  claim 1 , wherein the laser is a mode-locked laser. 
   
   
     6. The method according to  claim 1 , further comprising:
 collecting radiation applied to the brain tissue. 
 
   
   
     7. The method according to  claim 1 , wherein said identifying is carried out under conditions effective to determine whether the mammal has a neurodegenerative disease selected from the group consisting of Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, and Lou Gehrig's Disease. 
   
   
     8. The method according to  claim 7 , wherein said identifying is carried out under conditions effective to determine whether the mammal has Alzheimer's Disease. 
   
   
     9. The method according to  claim 8 , wherein amyloid plaques are detected in the brain of the mammal. 
   
   
     10. The method according to  claim 8 , wherein neurofibrillary tangles are detected in the brain of the mammal. 
   
   
     11. The method according to  claim 1 , wherein the method is carried out in vivo. 
   
   
     12. The method according to  claim 1 , wherein the radiation is passed through a portion of the skull of the mammal which has been thinned. 
   
   
     13. The method according to  claim 1 , wherein the fluorescence characteristic is an autofluorescence characteristic. 
   
   
     14. The method according to  claim 1 , wherein the radiation has a wavelength of about 700 nm to about 1000 nm. 
   
   
     15. The method according to  claim 1 , wherein the radiation is applied through an opening of the mammal's skull. 
   
   
     16. A method of producing an image of brain tissue from a mammal comprising:
 activating brain tissue of a mammal with radiation applied from a laser through an opening or a thinned portion of the mammal's skull under conditions effective to promote a simultaneous multiphoton excitation of the brain tissue and to produce a fluorescence, wherein the radiation is at an intensity level capable of being achieved by a titanium sapphire mode locked solid state laser and has a wavelength in the visible red to the infrared region of the light spectrum and is pulsed at a pulse width between about 10 −9  to 10 −15  second, said fluorescence being achieved by combining photons and 
 collecting the fluorescence to produce an image of the brain tissue. 
 
   
   
     17. The method according to  claim 16  further comprising:
 treating the brain tissue with at least one photo-active agent prior to said activating. 
 
   
   
     18. The method according to  claim 16 , wherein the laser is a mode-locked laser. 
   
   
     19. The method according to  claim 16 , wherein the method is carried out on brain tissue affected with a neurodegenerative disease, whereby said collecting produces an image of the brain tissue affected with a neurodegenerative disease. 
   
   
     20. The method according to  claim 19 , wherein said collecting is carried out under conditions effective to produce an image of the brain tissue affected with a neurodegenerative disease selected from the group consisting of Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, and Lou Gehrig's Disease. 
   
   
     21. The method according to  claim 20 , wherein said collecting is carried out under conditions effective to produce an image of the brain tissue affected with Alzheimer's Disease. 
   
   
     22. The method according to  claim 21 , wherein amyloid plaques are imaged in the brain of the mammal. 
   
   
     23. The method according to  claim 21 , wherein neurofibrillary tangles are detected in the brain of the mammal. 
   
   
     24. The method according to  claim 16 , wherein the method is carried out in vivo. 
   
   
     25. The method according to  claim 16 , wherein the radiation is passed through a portion of the skull of the mammal which has been thinned. 
   
   
     26. The method according to  claim 16 , wherein the fluorescence is autofluorescence. 
   
   
     27. The method according to  claim 16 , wherein the radiation has a wavelength of about 700 nm to about 1000 nm. 
   
   
     28. The method according to  claim 16 , wherein the radiation is applied through an opening of the mammal's skull.